1. Field of the Invention
The present invention is directed to hydraulic mining, and more specifically the hydraulic mining of coal while using pressurized oil at elevated temperatures and the subsequent transportation thereof by pipeline.
2. Prior Art
Hydraulic mining systems which utilize water under pressure are old and well known in the art. In such systems, the ore is generally loosened or disintegrated by the force of the water and the resultant slurry is piped to the surface for separation. However, such separation procedures are extremely costly and time consuming, and in certain instances the ore must be fully dried before it is useable in the further processing.
The chemical mining of coal is also known in the art wherein the coal seam is exposed to hydrogenating agents to produce a liquid product or other compounds which will weaken the interlayer forces at natural interfaces present in the coal to disintegrate the seam into fragments. Such chemical processes are very expensive due to the cost of the chemicals involved.
The use of oil for under water mining of mineral deposits is known wherein the loosened material will float to the surface of the water with the oil for recovery. However, such a system requires extremely large and complicated retaining devices to limit the floating oil and minerals to a restricted surface area and the cost of separating the water from the oil minerals renders such a process prohibitively expensive.
Finally, although the existence of coal/oil suspensions are known per se and although slurrys of coal and water have been transported long distances by pipeline no one has contemplated the production of the coal/oil suspension in situ at the coal seam by utilizing a jet of oil under pressure and the subsequent direct transportation of the coal oil slurry or suspension by means of a pipeline.